Unknown Flower, Mesmerizing Journey

Unknown Flower, Mesmerizing Journey (未知の花 魅知の旅,Michi no Hana, Michi no Tabi)
is an official doujin album by Team Shanghai Alice
released on 2011-05-08 (Reitaisai 8). It's a small addition to the "ZUN's Music Collection" series, so ZUN decided to number it "vol.5.5" instead of "vol.6".